Go Go Gadget Arms

iTrader: (2)

I am finally fed up with the lt1 i swapped into my truck, i just cracked my newly repaired heads and im tired with the aged obd1 electronics and opticrap.

Im looking at swapping in an ls1 or lq9. i cant decide which route i want to go. i plan on putting a cam, rockers, dyno tune. by the looks of where i want

power i will also be running a ls1 style intake.

Pros to ls1: aluminum block
ls1 intake
cons: expensive compared to iron block
front drive will need to be swapped to truck style

pros to lq9: 6.0L
more power/ torque
cheaper
cons: Iron block
intake to be swapped to ls style.

my goal is to hit 400-450 crank hp and have good low range torque, but be able to be reved to redline all day long. road race style.

heres what it going into.

-Greg

PowerShift408

iTrader: (44)

I vote LS1 on the basis of lighter weight. The only time I feel an iron block is the better choice is in big power adder situations. I feel the weight difference would greatly benefit a vehicle such as your truck.

Go Go Gadget Arms

iTrader: (2)

what does a complete ls1 and lq9 weigh, i just got the front suspension dialed and i really dont want to adjust spring rates and compression valving if the lq9 weighs more than the lt1

71-Camaro-98

iTrader: (17)

I think either or would work great, you can reach that power easy with either block and as long as the components are right, it should be up to the challenge. If I remember correctly the iron block is only somewhere around 65lbs heavier but in your kind of application that would make a big difference.

71-Camaro-98

iTrader: (17)

Here is what I have found...

LS Bare Block with liners:

(LS) Al = 107 #
(LQ) Fe = 172# (+65#)

Juicy J

iTrader: (5)

First off, cool truck. That looks like a hell of alot of fun.

In an application like yours, weight is very important, and the aluminum based LS motors will obviously suite your needs best.

It would be wise of you to check in the road racing, and Gen III Internal sections to see what you can do to make the engine more reliable in an extreme application like yours.

You definitely would want to change out the valvetrain components. Stock pushrods, and springs are not going to be your friend when you are revving to the moon all day long. You may also run into oiling issues.

Go Go Gadget Arms

iTrader: (2)

Good info thanks, it looks like the lt1 is about 535lbs complete and a ls1 is about 457 complete out of crate. The lq9 looks to be about 522lbs, which would enable me to drop it in with out any change in front suspension... It seems like i will get more bang for my buck for the LQ9.

what upgrades should i add besides LS6 intake?
any specific part numbers to hit my HP mark?
are rod bolts and re sized rods necessary like in the LS1?
1.7 or 1.8 rockers?
fuel rails necessary?
bigger injectors?
id like to run a cable throttle body what is needed? different pcm/ harness?
oil pump?

a parts list would be great

bww3588

iTrader: (49)

my opinion....

stock LQ9 longblock with hardened pushrods, LS7 lifters and rebuilt LS1 rocker arms.
LS6 intake, stock rails, get injectors that will work with whatever cam your putting in it.

take the bottom end apart, resize the rods and change all the bearings and rings. freshen up the cylinder walls with a brush hone. mic the crank and make sure its not out of spec, and check the main bores. you should be ok with stock main bolts but run ARP rod bolts. while you have the shortblock apart, take a die grinder and deburr the oil drainbacks in the valley to improve the oil return.

change the oil pump to a ported LS6 pump, and look into a pan from Canton Racing with oil control doors in the sump to keep the pickup submersed. i think you should be good from there.

Juicy J

iTrader: (5)

^This is all good advice.

You can just use stock LS1 rocker arms, rails, and the stock injectors really should be up to the task. You really just need bolt on's to get 400fwhp. A small to mid sized cam should get you to 450fwhp.

Follow bww's advice on the bottom end, and oiling. Its all very good advice.

bww3588

iTrader: (49)

thankyou for the +1 juicy.

i would go with a 228R cam, or somthing to that nature. something that makes power up top as well as equally as good power under the curve. maybe even a torqer V3 or something like that.

something i left out, with the LQ9, i think you should already have the 317 heads. these are great heads, they just have a huge chamber. mill them down a little bit to get a tighter squeeze on the mix and they should be good to go. get some springs to match the cam too.

Juicy J

iTrader: (5)

I would agree with your cam advice as well. The torquer is probably as big as the op would want to go, but I think it would work well for him. That would give him decent mid range, and good peak numbers as well. The torquer would easily exceed the OP's power goals, which I don't think he could complain about.

Anything larger than that, and it starts getting kind of peaky which would better be suited for drag racing.

Out of curiosity, how much does that truck weigh gadget?

bww3588

iTrader: (49)

idk what kind of drive train is in the truck, but i bet RWHP would be closer to his 400-450 goal than crank HP

Juicy J

iTrader: (5)

It would no doubt be in between 400-450rwhp. I don't know if the OP realizes how easy it is to make power with these engines.

Go Go Gadget Arms

iTrader: (2)

The truck weighs around 4k or less with 32 gals of fuel. Driver. Co driver etc. It has 35" bfg projects, but once i get the motor set up im going to upgeade to 37's. The trans is a th400 fixed yolk rv trans. Relatively stock, it shows no sign of wear after over 3000 racing miles and 2 years

i would like to run speed density, as maf's dont hold up to the vibration and conditions its in. Is a throttle cable tb possible? Or do i have to retrofit a fly by wire pedal.

71-Camaro-98

iTrader: (17)

LQ9 would easily get the power and with such a close weight to the LT1 it would save you some major time. Just like everyone else said above.

bww3588

iTrader: (49)

if you use an LS1 computer(or truck whatever) and a truck TB it will be cable TB. just watch, cause some of the trucks are DBW (03 + i think) and the older ones (99-02) are cable. you will most likely have to change the converter, because the power of the LQ9 comes on quite a bit later than the LT1. and will likely make more.

Go Go Gadget Arms

iTrader: (2)

The converter i have is only 2300rpm i think. The reasoning for low stall is that the trans will start to cook with the higher converter stall speeds. This is a basic rule of longevity for offroad transmissions we have learned otherwise i would run something more aggressive

Juicy J

iTrader: (5)

When you are ready to start looking at cams, there are two members that are well known for specing cams out for people. Their screen names are Predator Z, and Patrick G.

Running such a small stall is going to bring up a dilemma in choosing your cam. You might tell one of them your exact set up, and what you want out of your cam. They would be able to set up a cam to your exact needs.

bww3588

iTrader: (49)

or just run a big tranny cooler with an auxliary fan dedicated to the trans cooler.

Go Go Gadget Arms

iTrader: (2)

^ i run 2 pwr coolers with 12" fan. Summer races are usually +100*F and trans temp usually sits at 240-260*F from the reading in the trans pan sensor. My buddy who runs a strong ls1 in his 5200lb truck and a built cal performance trans gets his up to 290 in the sand washes.

Im sure i could bump the stall speed up as long as i change my R&P for the appropriate powerband and i should be fine